(a) Technical Field
The present invention relates to a reservoir for transmission fluid, such as ATF (Automatic Transmission Fluid). More specifically, a reservoir for ATF that can rapidly heat ATF with a PTC (Positive Temperature Coefficient) thermistor upon power being applied, and keep the ATF warm to be able to be used during cold-starting.
(b) Background Art
As is well understood by those skilled in the art, automatic transmissions require the use of ATF to work properly. As such the properties of the ATF have a significant impact on the efficiency, durability and operability of the transmission.
The ATF functions as a medium that carries torque from an engine to the axle. In particular, the viscosity of the ATF decreases in an inverse proportion to increases in temperature. Therefore, when the temperature of the ATF is too high, the transmission efficiency decreases and fuel efficiency reduces, whereas when the temperature of the ATF is too low, a shock is generated during shifting. Accordingly, it is preferable to keep the temperature of the ATF within an appropriate temperature range in order to prevent loss of power, reduction of fuel efficiency, and a reduction in vibrations.
To this end, some vehicles are additionally equipped with a warmer that rapidly increases the temperature of the ATF in the early stage of starting the vehicles and/or with an oil cooler that cools overheated ATF, depending on the type of vehicle in which it is installed. Typically, an oil cooler is integrally formed with a radiator at the front of vehicles to cool the coolant.
The warmers of the related art, however, typically use heat generated from the engine as a heat source.
However, when the engine is still cold, this heating method is ineffective. Furthermore, these types of heaters do not directly heat the fluid, but instead exchanging heat with a coolant. Therefore, it takes a time to increase the temperature of a coolant which is cold, so a new device that can more quickly heat ATF is required.
Further, since the oil cooler for cooling ATF and a warmer are individually connected, the spatial efficiency of an engine room is decreased.